Active compression adhesive packaging method and apparatus

ABSTRACT

A method and system for packaging products in a container employs an active compression assembly having pressure members which are shifted from a raised position to a lowered operational position. In the operational position, each pressure member holds a respective upper container flap against a lower container flap while an interposed adhesive sets. More specifically, with the at least one pressure member pushing upon the upper flaps, both the container and the at least one pressure member are forced to move in unison along a manufacturing line while the at least one pressure member applies pressure on the upper flaps as the adhesive sets to seal the upper flaps to the lower flaps and close the upper opening.

FIELD OF THE INVENTION

The invention pertains to the art of packaging and, more particularly,to packaging various products, such as food products, in containers orcases having folding upper and lower flaps which are adhesively attachedto close the container.

BACKGROUND OF THE INVENTION

Numerous manufactured products are pre-packaged, either individually orin groups, and then a plurality of the pre-packaged products arepackaged in a larger container and shipped to a wholesaler who unpacksthe container and places the pre-packaged products on display shelvesfor purchase by consumers. In particular, it is common to package a widerange of products in containers having folding flaps, such as cardboardboxes. Often in the manufacturing of products at many existingfacilities, the pre-packaging of the products is performed by automatedequipment, while the packaging of the various products into a largercontainer for shipping or storage purposes is performed manually. Forinstance, it is still commonplace for manufactured products to beconveyed to an assembly line region supplied with containers whereinassembly workers manually fill and seal the containers for shipping.However, in other situations, shipping containers can be loaded andsealed using automated machinery.

When utilizing cardboard boxes, each box is generally erected, eithermanually or with the use of machinery, to erect the box so as to createa packaging chamber having an open top which can be closed by foldingminor and major flaps. Once the box is erected, the chamber can befilled with products, either pre-packaged or not, and then the minor andmajor flaps are folded for shipping. Of course, it is desirable toprevent the box from opening prior to reaching its destination such thatit is common practice to seal the flaps. Basically, two methods arealmost universally employed to perform this sealing function. The firstis to externally apply adhesive tape along seams of the major flaps,with the tape generally being in the order of a couple inches in widthand extending across the top and onto opposing sides of the box. Theother approach is to apply an adhesive to the upper surfaces of theminor flaps after they are folded, then fold the major flaps onto theminor flaps so that the adhesive is also placed in contact with themajor flaps, and finally compress the major flaps onto the minor flapsfor a period of time to enable the adhesive to set to a certain extent.

This second approach is considered advantageous in that it can be morereadily automated. Unfortunately, there are at least two potentialproblems associated with this sealing method. The first problem onlyarises if the products being packaged are not solid in nature. That is,when the products being packaged are both generally solid in nature andfill the box to the fold seams associated with the flaps, the box can beeasily sealed in this manner as the products provide the back pressureneeded to hold the major flaps against the minor flaps while theadhesive sets. An example of such an arrangement would be packagingreams of paper in a box. However, if the products are not solid innature, the products cannot provide the back pressure necessary toenable the major flaps to be adequately compressed against the minorflaps such that the seal is inherently compromised. For instance,various products are pre-packaged with considerable headspace, includinga wide range of food products such as bags of potato chips, frozenvegetables, frozen biscuits, marshmallows and the like, which preventthe products from providing the requisite back pressure. The otherproblem concerns the downtime associated with sealing a box in thismanner. That is, although quick dry adhesives are commonly employed, theboxes being sealed need to be paused during the overall manufacturingprocess, such as for about 5-10 seconds, during which time flap staticbars hold the flaps in the folded position until the adhesive sets.Certainly, incorporating a mandatory pause in a portion of amanufacturing operation is not optimal.

Based on the above, there is seen to still exist a need for an moreefficient way of adhesively sealing packaging boxes in a manufacturingoperation wherein the box sealing operation can occur in a continuousprocess. In particular, there exists a need for a packaging operation,which can be employed in connection with products which do not terminatedirectly adjacent flap seams of the boxes and/or do not provide therequisite back pressure needed for forcibly sealing the flaps, whilealso enabling the flaps of boxes to be adhesively sealed in a continuousoperation.

SUMMARY OF THE INVENTION

The invention is directed to a method and system for packaging productsin a container, defining a compartment with an upper opening which canbe closed by adhesively securing foldable upper flaps upon lower flaps,along a manufacturing line. In accordance with the method and system ofthe invention, at least one pressure member of an active compressionassembly is shifted from a raised, home position to a lowered,operational position against the upper flaps. In the operationalposition, each pressure member holds a respective upper flap against alower flap while the interposed adhesive sets. More specifically, withthe at least one pressure member pushing upon the upper flaps, both thecontainer and the at least one pressure member are forced to move inunison along the manufacturing line while the at least one pressuremember applies pressure on the upper flaps as the adhesive sets to sealthe upper flaps to the lower flaps and close the upper opening. Toassure the unison movement, a leader member, which is attached to the atleast one pressure member, is positioned against a frontal portion ofthe container for a predetermined distance along the manufacturing line.Thereafter, the leader member is shifted to a retracted position and theat least one pressure member is shifted away from the upper flaps suchthat the entire system can be shifted back to a home position for use inclosing a subsequent container.

In operation, an open, assembled and loaded container is directed to aterminal portion of the manufacturing line wherein the lower flaps arefolded, followed by the application of adhesive to surface portions ofthe lower flaps and then folding of the upper flaps. At this point, theposition of the container is sensed such that, as it reaches and engagesthe leader member, the pressure member(s) of the active compressionassembly is lowered against the upper flaps. Thereafter, the pressuremember(s) engages the container, the pressure member(s) and thecontainer continue down the line in unison. During this time, the forceexerted by the pressure member(s) can be increased by further loweringthe same. After the container reaches another predetermined position,the leader member is retracted from in front of the container and theactive compression assembly is repositioned to act on another container.In this manner, an automatic, continuously operating active compressionoperation is performed to assure a high quality seal of the containerflaps.

Additional objects, features and advantages of the invention will becomemore readily apparent from the following detailed description when takenin conjunction with the drawings wherein like reference numerals referto corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a terminal portion of a manufacturingline including the packaging system of the invention, with a containerbeing shown in an initial closing stage.

FIG. 2 is a perspective view of the terminal portion of FIG. 1illustrating the container in an intermediate closing stage.

FIG. 3 is a perspective view of the terminal portion of FIG. 1illustrating the container in a final stage.

FIG. 4 is a perspective view of an active compression assembly employedin the packaging system of FIGS. 1-3.

FIG. 5 is a partial exploded view of the active compression assembly ofFIG. 4.

DETAILED DESCRIPTION OF EMBODIMENTS

With initial reference to FIG. 1, a terminal portion of a manufacturingline is generally indicated at 5. As shown, terminal portion 5 includesupstanding support framework 8 and a substantially horizontal supportframework 10. Horizontal support framework 10 rotatably supports aplurality of rollers 13, as well as a pair of side housings 18 and 19 inwhich are positioned endless side belts 22 and 23 driven by respectivemotors (not shown). As also illustrated in this figure, terminal portion5 is provided with a pair of opposing side guide rollers, one of whichis indicated at 27, as well as a pair of upper guide rollers, one ofwhich is indicated at 29.

As will be described more fully below, a container 33 is adapted to beloaded and directed down terminal portion 5 where it is sealed in afinal packaging stage of an overall manufacturing process. Althoughcontainer 33 can be made of various materials, including cardboard,container 33 includes a bottom 36 and opposing sets of upstanding sides38, 39 which define a compartment or chamber (not labeled) with anassociated upper opening 42. Upper opening 42 can be closed by folding apair of lower or minor flaps 45, followed by a pair of upper or majorflaps 46. More specifically, as will be detailed more fully below, lowerflaps 45 are initially folded along side seams (not labeled) and then,after an application of hot melt adhesive upon lower flaps 45, upperflaps 46 are folded and adhesively secured in order to close upperopening 42. To this end, container 33 is initially loaded with variousproducts 53 prior to reaching terminal portion 5. At this point, itshould be recognized that container 33 can be designed to receive a widevariety of products 53. However, for reasons which will be more fullyevident below, the present invention is particularly advantageous foruse in combination with products 53 which are not loaded all the way upto the fold seams for lower and upper flaps 45, 46 and/or areprepackaged in bags or the like with the inclusion of head space, e.g.,bags of potato chips, pretzels, frozen vegetables, frozen biscuits,marshmallows and the like, such that products 53 cannot provide therequisite back pressure upon lower flaps 45 needed to prevent lowerflaps 45 from pivoting within container 33 beyond a substantiallyhorizontal position. In any case, as container 33 reaches terminalportion 5 full of products 53, container 33 reaches a lower flap foldingmechanism 56 which functions to engage and fold lower flaps 45 into asubstantially horizontal plane as generally indicated in this figure.Although lower flap folding mechanism 56 can take various forms inaccordance with the invention as such flap folding mechanisms are knownin the art, the preferred embodiment employs one or more verticallymoving arms, such as that indicated at 59, which, timed with themovement of container 33 along the manufacturing line, abuts and pushesdown lower flaps 45 to the folded position. Subsequent to the folding oflower flaps 45, container 33 reaches an adhesive dispenser 62 whichapplies a predetermined amount of a hot melt adhesive 63 upon lowerflaps 45. Thereafter, continued movement of container 33 upon rollers 13causes upper flaps 46 to engage upper flap folding arms 64. At thispoint, it is the intent that upper flap folding arms 64 will cause upperflaps 46 to fold over at least portions of lower flaps 45 with the hotmelt adhesive 63 therebetween such that upper flaps 46 will be attachedto lower flaps 45 in order to close upper opening 42 of container 33.

In accordance with the invention, an active compression assemblygenerally indicated at 75 is added to terminal portion 5 of themanufacturing line in order to ensure that upper flaps 46 are positivelyengaged with lower flaps 45 during a critical period in which adhesive63 sets, thereby ensuring that upper opening 42 is adequately sealedsuch that additional tape over upper flaps 46 is not necessary. Withparticular reference to FIGS. 4 and 5, active compression assembly 75will now be detailed. In the illustrated embodiment, active compressionassembly 75 includes an upright support 78 from which extends acantilevered arm 82. A gusset plate 83 interconnects upright support 78and cantilevered arm 82 for additional support. Mounted to cantileveredarm 82 is a rail or track 87 upon which is slidably mounted a guide unit90. As shown, guide unit 90 includes a grooved plate 93 which mates withrail 87. Although not shown for the sake of simplicity of the drawings,an additional grooved plate is positioned on the other side of rail 87and is interconnected with groove plate 93 to clamp guide unit 90 forsliding movement along rail 87. In addition, the structure of rail 87and/or groove plate 93 can be made of a low friction material or variousrollers, bearings or the like can be interposed therebetween in order toease the linear shifting of guide unit 90 along rail 87. As movement ofguide units along rails are widely known in the manufacturing field andthis is not considered to be a particular aspect of the presentinvention, further details thereof will not be provided here. Moreimportantly, guide unit 90 also includes a housing 96 that is fixedrelative to plate 93 and formed with a pair of spaced bores 103 and 104.Spaced bores 103 and 104 slidably receive guide bars 107 and 108 thatare attached to a vertically displaceable base plate assembly 112. Afirst drive mechanism 116 is interposed between housing 96 and baseplate assembly 112 to vertically shift base plate assembly 112 relativeto housing 96. More specifically, first drive mechanism 116 includes alinear actuator 119 defined by a cylinder 122 and a piston rod 125. Atthis point, it should be recognized that linear actuator 119 can takevarious forms in accordance with the invention, including pneumatic,hydraulic and electric solenoid-type linear actuators. Therefore, it isonly important to note that first drive mechanism 116 provides for theselective vertical shifting of base plate assembly 112 relative tohousing 96 and rail 87.

Also carried by base plate assembly 112 is a second drive mechanism 130.Second drive mechanism 130 is also defined by a linear actuatorincluding a cylinder 136, which is fixed relative to base plate assembly112, and a piston rod 139 which is movable relative to cylinder 136.Piston rod 139 is attached by means of a pin 143 to a pair of arms 146and 147 extending from a rod 149 that is rotatably mounted in a pair ofleg members 152 and 153 secured to base plate assembly 112. Alsoextending from rod 149 for concurrent rotation therewith is a leadermember or drag arm 156. In the embodiment shown, leader member 156includes a main body 158 and a terminal abutment member shown in theform of an extruded metal tube 160. With this arrangement, extension andretraction of piston rod 139 relative to cylinder 136 causes arms 146and 147, as well as rod 149 and leader member 156, to rotate about anaxis defined by rod 149. More specifically, retraction of linearactuator 133 from the extended position shown in this figure causesleader member 156 to shift from a substantially vertical plane asdepicted to a substantially horizontal plane.

As will be detailed more fully below, active compression assembly 75 isemployed to provide pressure upon upper flaps 46 during a criticaldrying period for adhesive 63, thereby providing an enhancedinterconnection between upper and lower flaps 46 and 45. In addition, itis desirable to construct active compression assembly 75 in a mannerwhich will accommodate varying sized containers 33. In accordance withthese aspects of the invention, base plate assembly 112 includes a mainportion 168 formed with a plurality of spaced openings 171. A respectivepressure member 175 is mounted in each of the openings 171 as will bediscussed further below. Each side of main portion 168 is also providedwith an elongated slot 185 which generally extends in the direction ofrail 87. Portions of each slot 185 are aligned with a slot 188 in arespective extension arm 190, with each extension arm 190 receiving anadditional pressure member 193 in a respective opening 171. With slots185 and 188 aligned, a respective bolt 196 extends through the slots soas to secure extension arm 190 to main portion 168. With the provisionof slots 185 and 188, or an analogous arrangement including a pluralityof holes, it should be readily apparent that extension arms 190 can bemounted at various angular positions and to establish differentdistances between the plurality of pressure members 175, 193. In thisfashion, base plate assembly 112 can be readily reconfigured fordifferent size containers 33.

It is the function of pressure members 175 and 193 to apply downwardforces upon upper flaps 46 to ensure a positive pressure between upperflaps 46 and lower flaps 45 during a critical setting period for theadhesive. For this purpose, each of the pressure members 175 ispreferably made of a resilient material, such as an elastomeric orrubber material. More specifically, each pressure member 175 includes ahead 202, a shank 204 and a flexible finger portion 206. Flexible fingerportion 206 is inserted into a respective opening 171 and shank portion204 preferably defines a reduced diametric portion (not labeled)directly adjacent head 202, with the reduced diametric portion beingslightly greater than the thickness of either main portion 168 orextension arm 190. In this fashion, each pressure member 175 can befrictionally maintained in place by simply pulling on shank portion 204until head 202 is positioned against either main portion 168 orextension arm 190. In any case, finger portion 206 is made more flexiblethan shank 204 and therefore will resiliently bend to apply the desiredpressure as will be described in detail below. In the embodiment shown,the controls associated with active compression assembly 75 arepneumatic in nature such that various air hoses 225-229 are illustratedin FIGS. 1-3, including hoses extending to linear actuators 119 and 133.

As discussed above, in the position shown in FIG. 1, container 33 haslower flaps 45 folded in and adhesive dispenser 62 has applied theadhesive 63 thereon. Container 33 then proceeds wherein upper flaps 46engage folding arms 64. At this point, container 33 reaches the positionshown in FIG. 2 where a frontal portion of container 33 abuts terminalabutment member 160 of leader member 156, with main body 158 of leadermember 156 extending substantially vertically. At this time, linearactuator 119 of first drive mechanism 116 is activated such that pistonrod 125 is extended and base plate assembly 112 shifts relative tohousing 96 such that the plurality of pressure members 175 and 193 comeinto engagement with predetermined sections of upper flaps 46. Given theconstruction of base plate assembly 112 as described above, the exactposition of at least pressure members 193 can be readily adjusted. Inthe present case wherein lower flaps 45 do not extend the entire widthof container 33 as clearly shown in these figures, extension arms 190are angled inwardly such that pressure members 193 abut adjacentcenterline portions of upper flaps 46, while pressure members 175 abutmore central portions of upper flaps 46. Given the resilient nature ofpressure members 175 and 193, the downward movement of base plateassembly 112 causes flexible finger portions 206 to bend, therebyapplying the requisite degree of pressure for setting of adhesive 63.

In accordance with a preferred embodiment of the invention, it isdesired to time the positioning of container 33 with the movement offirst drive mechanism 116 such that a sensor 255 is employed to detect afrontal edge portion of container 33 along terminal portion 5 of themanufacturing line. In the embodiment shown, a photo eye 256 cooperateswith a reflector 258 to sense this leading edge. However, it should beunderstood that various types of sensor systems, including switches,could be employed. Once active compression assembly 75 is engaged withcontainer 33, container 33 reaches endless side belts 22 and 23 to carrythe container 33 to the terminal portion 5 of the manufacturing line. Atthe same time, guide unit 90 carries base plate assembly 112 along rail87 in unison with the movement of container 33. Although guide unit 90could be driven in this direction by endless side belts 22 and 23 andcontainer 33 given the abutment between container 33 and leader member156, the most preferred form of the invention provides a separate lineardrive mechanism, such as a horizontal, rodless air cylinder (not shown),to move guide unit 90 along rail 87 in unison with container 33. Inaccordance with one aspect of the invention, a progressively increasingvertical application pressure is applied to vary the force exerted bypressure members 175 and 193 upon container 33 as base plate assembly112 is guided along rail 87 as evident in comparing at least FIGS. 2 and3. Upon reaching the end of its operational movement, second drivemechanism 130 is activated to rotate leader member 156, while firstdrive mechanism 116 functions to vertically shift pressure members 175and 193 out of engagement with upper flaps 46 and active compressionassembly 75 is returned to the ready position shown in FIG. 1. To signalthese operations, it is desirable to provide a second sensor generallyindicated at 275. In the configuration shown, second sensor 275 isconstituted by a switch 276 that becomes engaged with an abutment member278 carried by housing 96 of guide unit 90. In other embodiments,different sensors, such as another photo eye, could be employed.

Based on the above, it should be readily apparent that the activecompression assembly of the invention enables at least one pressuremember to be shifted from a raised, home position spaced from the upperflaps of the container to a lowered, operational position in which thepressure member abuts and applies pressure to respective upper flap inorder to hold the upper flap in a desired position while the adhesivebetween the upper and lower flaps sets. During this period of positivepressure, both the container and the pressure member move in unisonalong the manufacturing line until a predetermined point where thepressure member is moved away from the upper flap and back to the homeposition. As it is not desirable for the pressure members to sliderelative to the container during this operation, the leader member isprovided to prevent the container from moving at a faster pace than thebase plate assembly of the active compression assembly. That is, theleader member is maintained in an active position during the concurrentmovement and then is shifted to a retracted position to enable theactive compression assembly to be repositioned for use in closing asubsequent container coming down the manufacturing line. Again, althoughthe invention can be employed in connection with containers which arefilled up to the fold lines for the upper and lower flaps and whichcould provide back pressure to enable the upper flaps to be pushedagainst the lower flaps without deflection of the lower flaps, theinvention finds particular applicability for use in sealing containerswhich are filled with products that cannot provide the requisite backpressure. In such an arrangement, it is desired to mount the pressuremembers generally close or only slightly spaced from the fold lines ofthe lower flaps, thereby minimizing any undesirable added deflection ofthe lower flaps while still assuring a positive pressure between theupper and lower flaps for setting of the adhesive. It has been foundthat the invention is extremely productive in ensuring that a strongadhesion is created between the upper and lower flaps such thatadditional taping of the container is not necessary.

Although described with reference to certain embodiments of theinvention, it should be readily understood that various changes and/ormodifications can be made to the invention without departing from thespirit thereof. For instance, the type of product, the containermaterial, the location, mounting and structure of the pressure members,and also the exact drive and interaction between the active compressionassembly and the container can be altered without departing from theinvention. Instead, the invention is only intended to be limited by thescope of the following claims.

1. A method of packaging products comprising: directing a container,defining a compartment with an upper opening which can be closed byfolding upper and lower flaps, along a manufacturing line; positioning aplurality of products in the compartment of the container; folding alower flap over a portion of the upper opening; folding an upper flapupon the lower flap with adhesive there between; shifting at least onepressure member of an active compression assembly from a home positionspaced from the upper flap to an operational position against the upperflap; directing both the container and the at least one pressure memberto move in unison along the manufacturing line while the at least onepressure member applies pressure on the upper flap as the adhesive setsto close the upper opening; and shifting the at least one pressuremember away from the upper flap and moving the active compressionassembly back to the home position for use in closing a subsequentcontainer.
 2. The method of claim 1, wherein the adhesive is applied tothe lower flap following the folding of the lower flap and prior to thefolding of the upper flap upon the lower flap.
 3. The method of claim 1,wherein shifting the at least one pressure member comprises moving aplurality of spaced fingers into engagement with the upper flap.
 4. Themethod of claim 3, wherein the plurality of spaced fingers arevertically shifted into engagement with the upper flap.
 5. The method ofclaim 3, further comprising: selectively adjusting a spacing between theplurality of spaced fingers.
 6. The method of claim 3, furthercomprising: resiliently biasing the plurality of spaced fingers intoengagement with the upper flap.
 7. The method of claim 1, furthercomprising: shifting a leader member into a ready position forengagement with a frontal portion of the container to assure that boththe container and the at least one pressure member move in unison alongthe manufacturing line.
 8. The method of claim 7, further comprising:pivoting the leader member from a retracted position to the readyposition.
 9. The method of claim 1, further comprising: linearly guidingthe at least one pressure member along a track while both the containerand the at least one pressure member move in unison along themanufacturing line.
 10. The method of claim 1, wherein positioning theplurality of products in the compartment of the container constitutesloading the container with sealed packages having headspaces such thatthe sealed packages do not provide any significant back pressure to theupper and lower flaps when closing the container.
 11. The method ofclaim 10, wherein closing the container constitutes sealing a cardboardbox.
 12. A system for closing an upper opening of a container defining acompartment in which is positioned a plurality of products, the systemcomprising: at least one pressure member; a first mechanism drivinglyconnected to the at least on pressure member of an active compressionassembly for moving the at least one pressure member from a firstposition spaced from the container to a second, operational positionwherein the at least one pressure member engages an upper flap of thecontainer to force the upper flap towards a lower flap of the containerwith an adhesive there between; and a second mechanism connected to theat least one pressure member and causing both the container and the atleast one pressure member to move in unison along a manufacturing linewhile the at least one pressure member applies pressure on the upperflap as the adhesive sets to close the upper opening, wherein the firstmechanism can reposition the at least one pressure member away from theupper flap and the second mechanism can move the active compressionassembly back to a home position for use in closing a subsequentcontainer.
 13. The system of claim 12, wherein the at least one pressuremember comprises a plurality of spaced fingers.
 14. The system of claim13, wherein the first mechanism shifts the plurality of spaced fingersvertically into engagement with the upper flap.
 15. The system of claim13, wherein the active compression assembly includes first and second,adjustably connected plates, wherein at least one of the plurality ofspaced fingers is attached to the first plate and another of theplurality of spaced fingers is attached to the second plate, said secondplate being adjustably attached to the first plate to vary spacingsbetween the plurality of spaced fingers.
 16. The system of claim 13,wherein each of the plurality of spaced fingers is formed of a resilientmaterial.
 17. The system of claim 12, wherein the active compressionassembly further comprises a leader member mounted for movement betweena ready position for engagement with a frontal portion of the containerand a non-engaging, retracted position.
 18. The system of claim 17,wherein the leader member is pivotable between the ready and retractedpositions.
 19. The system of claim 17, further comprising: a sensor forsensing the frontal portion of the container at a predetermined locationalong the manufacturing line, with movement of the leader member beingdependent on the frontal portion being sensed.
 20. The system of claim12, further comprising: a sensor for sensing a position of the activecompression assembly along the manufacturing line, with movement of thesecond mechanism back to the home position being dependent on theposition of the active compression assembly.
 21. The system of claim 12,wherein the active compression assembly includes a track member, said atleast one pressure member being mounted for linear movement along thetrack member.
 22. The system of claim 12, wherein the containerconstitutes a cardboard box and each of the products is constituted by asealed package including a headspace.